Bimetallic key blank



` Sept. 29, 1953 H. ABRAMs 2,653,492 BIMETALLIC KEY BLANK Filed Aug. 10, 1951 11, 55 15 i@ rx i Z .-I--Zl-n IIIII' @4 l 7 1 f2@ 11 11. 1D ,f Z5

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IN V EN TOR. HowARu ABRAMS BY ATTORNEYS Patented Sept. 29, 1953 BIMETALLIC KEY BLANK Howard Abrams, Cleveland, Ohio, asslgnor to Curtis Industries, Inc., Cleveland, Ohio, a corporation of Ohio Application August 10, 1951, Serial No. 241,273

(Cl. 'I6-110) 7 Claims.

This invention relates to key blanks and the manufacture of the same, and more particularly to key blanks formed of dissimilar stock material.

In the manufacture of key blanks for ultimate use in locks such as those of the pin tumbler type, it has heretofore been the practice to punch the entire blank out of a selected kind of stock or material, such as brass, aluminum or noble metal alloys. It has been found that the above-mentioned metals have the requisite physical and chemical characteristics which experience has proven are necessary in a key blank.

Principal among these characteristics is that the shank of the key must be corrosion-resistant and malleable. rIhe need for corrosion-resistance is self-evident, as the key7 must be free from rust or scaling and must maintain its dimensional stability for an extended period of time. The blank must also be malleable or readily workable, so that the finishing operations performed ing portion of the key, that is, the shank. The

handle portion or knob of the key need not conform to these requirements, as it is used only to grasp the key. No work or finishing operation is necessary by the locksmith on the knob portion of the key, therefore it need not be as malleable as the shank. Therefore, the use of the identical metal for the knob as is used for the shank, is wasteful, unnecessary and uneconomical.

Normally, the metals and metal alloys heretofore mentioned as usable for key blanks, are in abundant supply and little concern is shown if such metals are used Wastefully. However, in periods when the supply of such metals is scarce, it is necessary to practice the utmost frugality in the use of metals and husband the supply thereof. This obviously means that these metals should, under such circumstances, be used only in those applications where their physical and chemical characteristics are indispensable.

It is a primary object :of my invention to provide a key blank structure in which the critical key blank metals are used solely for the insertable portion of the key, i. e., the shank and a less critical metal is utilized for the non-insertable portion of the key, i. e. the knob.

Another object of my invention is to provide a unitized key blank consisting of dissimilar metals.

Still another object of my invention is to provide a key blank of the character described hav- 2 ing a knob portion of dissimilar metal secured in a novel manner to a shank portion of more critical metal.

A further object of my invention is tc provide a key blank which will be more economical to manufacture as it will employ lesser amounts of the more expensive metals.

Other objects and advantages of my invention will be apparent during the course of the following description. ln the accompanying drawings forming a part of this specication and in which like numerals are employed to designate like parts throughout the same,

Fig. l is a plan view of a finished key blank embodying the features of my invention.

Fig. 2 is a longitudinal cross-sectional view taken on line 2-2 of Fig. l.

Fig. 3 is a plan View of the shank portion of the key blank prior to assembly.

Fig. i is a transverse cross-sectional View taken on line 4 4 oi Fig. l, and

Fig. 5 is an exploded view of the parts shown in Fig. 4.

Referring more particularly to the drawings, the reference character I0 designates a finished two-piece key consisting of a shank ll and a knob portion l2.

As best seen in Fig. 3, the shank Il is initially blanked out of a strip of suitable metal such as brass or the like, and is substantially rectangular in form, coming to an apex or point I3 at one end thereof. The opposite end of the shank has a punched out hole or aperture lll formed therethrough which may, as indicated, be circular.

Intermediate the two ends a shoulder or abutment l5 is formed which serves as a stop for the insertable portion of the finished key, as shown in Fig. 1.

The shank is then processed through cutters to form the milled grooves l@ and Il which extend longitudinally of the shank l l and conform to the contour of the keyhole opening.

The knob l2 of the key blank is formed out of two formed circular disks i8 and I9 which may be of light gauge steel or the like. As best seen in Figs. 4 and 5, the male disk I8 is provided with a rectangular embossment 2! which conforms to the shape of the shank Il and is complementary thereto. The height of the embossment ZIJ is such that the marginal portion 2l of disk I8 will extend over the sides of the shank for a distance substantially equivalent to one-half the thickness of the shank i I. The embossrnent 20 commences at the edge 22 of the disk I8 and extends diametrically to a point 23 short of the opposite i edge of the disk It?, thereby providing three side walls to embrace the shank. The parallel side Walls 24 and 25 embrace the sides of the shank I I, and the rear Wall 2t abuts the end of the shank.

The embossment 2t has a circular aperture 21 formed therein, having a dependent flange 28 which is of such lsize as to nest wthinft-he aperture Iii .of .the shank .I i.

The female disk i9 is complementary to the disk i3 and similarly is provided with a shank-f, f

at 33 to clear the shank II.

The flange 32 is adapted to be bent into overwhereby said knob completely encloses said end portion of said shank and is immovably secured thereto.

2. A key blank comprising a shank having an aperture adjacent one end thereof, and a knob secured to said end of said shank, said knob consisting of a pair of disks permanently secured in gface to :face abutment with eachother, each of said disks having an embossment .forming a shank-receiving cavity, the Walls of said cavity abutting opposite sides of said shank to lock said shank against transverse movement relatively to said disks, and each of said disks having an opening Itherein .defined by an annular flange integral therewith, said iianges extending into said :aperture :tolock said shank against longitudinal movement relatively to said disks.

lying relation to the disk I8 so as to secure Vthe 5 parts I8 and i9 together on the shank .I I. Eig 5 shows the parts prior to assembly, and Fig. 4 .shows the parts .assembled With .the Filange .32 rolled .or .crimped .over the Idisk I8, .to ...form 'the knob I2. A circular embossment or bead 34 is ,.ormedin thedisk I9 adjacent the Aflange 32 and .thus both sides of the knob I2 have substantially the same appearance, the .bead 34 being the counterpart of the rolled iiange 32. Further, .the rolled flange 32 .and the bead .34 provide vraised Vedges on the knob .I2 to .prevent slipping of the vusers ngers when the knob is grasped.

yThe vkey blank can .then .be readily .converted to a n-ished key by Acutting the shank to provide the proper combination of ridges 3.5, as seen `in Fig. l.

It will be noted the assembled key blank I 0 results in a rigid integrated .combination of the shank I I and the knob I2. The side walls ofthe `embossinents 2i) and 2,9 provide a Cavity in .which the shank II is securely .embraced so -that itis held in axial .alignment with the knob and any iw..

relative transverse or .twisting movement `of the shan'k is prevented. The angesZS and 3l .which project into the aperture I4 of the shank, prevent `any relative longitudinal movement of the ,shank :and thereby the shank is .completely immobilized relatively to the knob and rigidly `integrated therewith. As an additional feature vto prevent longitudinal Ymovement of the shank in lone direction, Athe rear Walls, such as the wall .25 .of the embossments .20 and t28 abut `tl'ierear -edge :of the shank II.

It will thus be .apparent that I have provided a birnetallic .key blank -in which .the yscarce land expensive `metals :are used solely where they .are required, that is, for the insertable or shank portion .of the key, and la less expensive and Ymore abundant vmetal is utilized for the non-insertable or knob portion of the key. The key thus -pro- Avided is economical Ito.manufacture and is sturdy and durable.

Having thus described my invention, I claim:

1. A key blank comprising a shank .having an aperture adjacent one end thereof, and a knob secured to said end of vsaid shank, said .knob .consisting of a pair Yof disks permanently securediin lface to face abutment With each other, ,each of said vdisks having an embossment forming a shank-receiving cavity, the Walls or" said cavity abutting said end and opposite sidesof said shank to a depth substantially equal to one-half the thickness of the shank, and a projection ,provided on .each vof said disks and extending into .said Vraperture .in .abutment with the wall thereof `3. A lkey'blankas defined in claim 2 in which said -walls of said cavity and said annular flanges extend substantially to a plane dening one-half the thickness of said shank.

.4. Akey blank comprising a .shank having lan aperture .adjacent one l.end thereof, and a .knob .secured to saidendof said shank, said .knob .consisting-of ,a pair of disks disposed in `face to face .abutment with each other, each of said disks having an embossment forming a shank-receiving cavity, the Walls `of .said cavity abutting opposite sides .of said shank to lock .said .shank against .pivotal movement relatively to said disks, .a projection vprovided on each of said disks and eX- tending into said aperture in engagement with the Wall thereof .to lock said shank against .longitudinal movement relatively to said'disks, and an annular ilange integral with one of said .disks and ybent into overlying relationship .to the `other ofsaid disks to permanently .secure .said .disks .to each other.

,5. A -key blankas A.defined in claim 4 in which the ,thickness of said .shank is substantially great- .erfthan .the thickness .of each .of said disks.

6. A key blank as defined in claim 5 in which Said disks are vmade `of metal and .said ,shank is .made of ldissimilar metal.

`7. A -key bla-nk .comprising Aa shank .having an aperture Vadjacent one .end thereof, and a .knob

,Secured to saidend ofsaid shank, said knob con- Vsisting of .a ,pair .of flat elements permanently secured .in face to face abutment with each other, each of .said elements .having an embossment forming ,a shank-receiving cavity, the walls .of

.said cavity ,abuttingopposite Asides of said shank to .lock said shankagainst transverse movement relatively to said elements, and each of saidelements having an Aopening therein defined by an .annular iiange integral therewith, said Vflanges l.extending .into `said aperture to 'lock said shank `against longitudinal movement lrelatively 4to vsaid elements.

AHOW/'ARD ABRAMS.

References vCited Vin the le of this patent UNITED STATES PATENTS 

